We can not think about a life without water.
That's why we hardly think about this very special substance.
Water is the most normal thing in the world to us.
However, it is worth to take a closer look at the not so normal fluid.
In chemical and physical view water is H2O.
However, this term indicates a lot of features which not all are comprehensible.
The dense anomaly is a famous feautre proving that water expands during freezing and therefore becomes less dense. Otherwise there would be no swimming icebergs or ice cubes swimming on the surface of cocktails.